How to treat complex frontal sinus disease, such as chronic frontal sinusitis, varies from condition to condition. Endoscopic transnasal performance of the DRAF III procedure is one option. The so-called DARF III requires the use of an angled endoscope to dissect the frontal sinus openings underneath the anterior skull base, creating a new system of left-right penetration (frontal sinuses on both sides) and midline drainage (frontal sinuses on both sides connected to a new nasal septal opening). The purpose of this is to completely solve the problem of blockage of the frontal sinuses, i.e. drainage. We can summarize such a design and practice in layman’s terms as anterior cranial base tunneling. I have previously published articles in this section, such as my own team’s use of a combined up-and-down approach to treat frontal sinus disease (published on 2012-10-21 and 2013-4-12), and another example, such as the introduction of the DARF III procedure using endoscopy by Bing Zhou at Beijing Tongren Hospital (2009-3-21). It is the latter procedure, DRAF III, that we are going to talk about today. It should be said that as a specialist who performs nasal endoscopic surgery, we naturally have a good idea of the anatomy of the frontal sinus, but we are often a bit bewildered by the change of anatomical position during surgery, the cause of local bleeding, etc. Today, we have successfully performed DRAF III from the nasal cavity by endoscopic technique, and a large amount of mucus similar to fungal infection was aspirated and flushed out from the frontal sinus cavity during the operation, and the post-operative cavity is like a gourd with a left-right connection, thin in the middle and thick on both sides, which is called “horseshoe-shaped” in the industry. It is called “horseshoe-shaped” in the industry, and foreigners or foreign language sources have a special name for this form: THE FRONTAL T, which means the T-shaped frontal sinus drainage tract formed after frontal sinus surgery. It should be explained that the upright stroke in the T corresponds to the part of the vertical plate of the sieve that connects to the anterior skull base, while the parallel stroke is the space of the newly created frontal sinus base and its channels. The main points of the operation are: to accurately identify the structures of the anterior skull base immediately adjacent to the frontal sinus floor (to prevent entry into the skull), to make the anteroseptal opening just right (neither too large nor too small), and to grind out the frontal sinus opening in the direction of the anterosuperior and maxillary frontal processes in sequence. By the way, if a supraorbital air space is seen before surgery, it must be carefully searched and positioned to be treated so that the hidden lesion does not affect the surgical result. With the accumulation of surgical experience, the problems encountered during surgery, the so-called bottlenecks, will gradually be solved one by one. Postscript: on 2015-11-13 (Friday), we performed a case of DRAF III surgery. This was a patient who had undergone nasal endoscopy about 10 years ago for nasal polyps combined with asthma, and this review revealed bilateral septal sinuses and frontal sinuses filled with polyps. On the basis of aggressive preparation, we performed the DRAF III procedure, which revealed a large air space in the left frontal sinus, while the true frontal sinus opening was squeezed into a fissure shape. This is a typical so-called type IV airspace (i.e. “sinus-in-sinus” SINUS-IN-A-SINUS). After complete opening of the atrium, it was found that the frontal sinus on the side had a secretion reservoir due to prolonged obstruction of drainage; at the same time, there was a round, isolated polyp-like object in the contralateral frontal sinus. In addition, this case developed an asthma attack after surgery, which was treated in the ICU and turned to safety. P.S. A frontal sinus balloon dilation procedure was recently (2015-12) performed. The seemingly simple positioning of the frontal sinus drainage port actually reflects the comprehensive clinical strength of the operator. However, having performed frontal sinus DRAF III surgery before, one has some experience and can still eventually locate and perform balloon dilation.